Add a NavigationThrottle to the public content/ interface

content/browser/loader/navigation_url_loader_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_LOADER_NAVIGATION_URL_LOADER_IMPL_H_
 #define CONTENT_BROWSER_LOADER_NAVIGATION_URL_LOADER_IMPL_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 22 matching lines @@
 
   // Called in response to OnRequestRedirected to continue processing the
   // request.
   void FollowRedirect() override;
 
  private:
   friend class NavigationURLLoaderImplCore;
 
   // Notifies the delegate of a redirect.
   void NotifyRequestRedirected(const net::RedirectInfo& redirect_info,
-                               const scoped_refptr<ResourceResponse>& response);
+                               const scoped_refptr<ResourceResponse>& response,
+                               bool is_external_protocol);
 
   // Notifies the delegate that the response has started.
   void NotifyResponseStarted(const scoped_refptr<ResourceResponse>& response,
                              scoped_ptr<StreamHandle> body);
 
   // Notifies the delegate the request failed to return a response.
   void NotifyRequestFailed(bool in_cache, int net_error);
 
   // Notifies the delegate the begin navigation request was handled and a
   // potential first network request is about to be made.
   void NotifyRequestStarted(base::TimeTicks timestamp);
 
   NavigationURLLoaderDelegate* delegate_;
 
   // |core_| is deleted on the IO thread in a subsequent task when the
   // NavigationURLLoaderImpl goes out of scope.
   NavigationURLLoaderImplCore* core_;
 
   base::WeakPtrFactory<NavigationURLLoaderImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationURLLoaderImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_NAVIGATION_URL_LOADER_IMPL_H_